Set-screw guard.



No. 761,708. PATENTED JUNE 7,1904.

' v 0. E. PIERCE.

SET somaw GUARD.

APPLIOATION FILED AUG. 3, 1903. N0 MODEL.

Y 6.7 2.7-" I .7153 W A U ITE STATES Patented June .7, 1,904.

PATE T OFFICE.

CHARLES E. PIERCE, OF CAMBRIDGE, MASSACHUSETTS.

SET-SCREW GUARD.

SPECIFICATION forming part of Letters Patent No. 761,708, dated June 7,1904.

Application filed August 3, 1903- 1'0 12,66 whom it may concern:

Be it known that I, CHARLES E. PIERCE, of Cambridge, in the county ofMiddlesex and State of Massachusetts, have invented certain bwhich Iwill now proceed to describe and claim.

Of the accompanying drawings, forming a part of this specification,Figure 1 representsv a transverse section of a shaft, together with I'an edge view of a guard embodying my invention, said guard beingapplied to a setscrew and collar on the shaft. Fig. 2 represents a sideelevation of the guard and a corresponding view of the shaft and collar.Fig.

- 3 represents a perspective vie-w of the guard.

Fig. 4 represents an elevation of the inner or underside of the guard.Fig. 5 represents a section on line 5 5 of Fig. 1. Fig. 6 represents aView similar .to Fig. 5, showing the parts in a different position.

The same reference characters indicate the same parts in all thefigures.

In. thedrawings, a represents a shaft, and 6 represents a collarthereon, the collar being secured to the shaft by a set-screw c. Thepart b may, however, be any rotary member which is secured in place by aset-screw projecting from its periphery.

My improved guard is composed of a single curved strip of resilientmaterial (preferably tempered steel) constituting a bridge extendingover theset-screw and comprising a central portion cl and arms 0? cl,integral with the central portion, the lower or outer portions of saidarms converging inwardly toward each oth er,so that their ends areseparated by a space of less width than the diameter of the collarSerial No. 167,981. (No model.)

or body 6. The bridge can therefore be engaged with the collar byplacing the ends of its arms against the periphery of the collar andapplying force tending to move the central portion of the bridge towardthe collar, the arms being thus caused to first spring apart until theypass over the center of the collar, the arms then springing inwardly andengaging the collar, as indicated in Fig. 1. The central portion d ofthe bridge is provided with a device for engagement with the set-screw0, said device being of such character that when the bridge has beenmoved to the position shown in Figs. 1 and 2 it cannot be moved edgewiseor in a direction parallel with the axis of the shaft because of the engagement of its central portion with the setscrew, the describedengagement of the arms CZ d with the collar preventing outward movementof the bridge unless a sufficient degree of force is employed to causethe armsd to swing outwardly.

In the present embodiment of my invention I have shown as the means forconnecting the central portion of the bridge with the setscrew a stripcof flexible material, (preferably sheet metal,) such as copper. Oneedge of said strip is attached in any suitable way (preferably by asolder connection 0') with the centralportion dofthe bridge. Theconnection 6 confines only ,a portion of the edge of the strip 6,leaving the other portions of the strip free to be bent into engagementwith the head of the set-screw. The connection 0 is preferably arrangedbetween the ends of the strip 6, so that the strip extends in the formof two arms from the connection 0', as clearly shown in Figs. 3 and 4:.Before attaching the strip 0 to the bridge I prefer to bend the strip,as shown in Fig. 4, so that it will bear against three sides of the headof the set screw, the length of thestrip being such that its endportions can be bent into engagement with the fourth side of theset-screw head, as shown in Figs. 5 and 6. The meeting ends of cated inFigs. 5 and 6.

of which the bridge is formed is such that it overhangs the socketformed by the flexible strip a, so that said socket does not projectfrom the edges of the bridge. The flexibility of the strip 0 enables itto be conformed to different positions of the head of the set-screw, asindicated in Figs. 5 and 6.

ItWill be seen that the device when in the condition shown in Fig. 3 canbe very quickly engaged With a collar 7) and set-screw c, the bridgebeing first forced onto the collar in the position required to cause thestrip a to bear upon three sides of the set-screw, after which the endsof the strip 0 are bent to complete the socket.

The bridge forms the outer side of a segmental space at one side of thebody I), the setscrew projecting into said space and being covered bythe central portion of the bridge. I may employ any suitableset-screW-engaging device affixed to the bridge and projecting into saidspace to cooperate With the resilient arms in holding the guard as aWhole firmly in position to guard the set-screw.

I claim 1. A set-screw guard comprising a resilient bridge having acentral portion and convcrging arms formed to engage a cylindrical body,and a set-screW-engaging device aflixed to the interior of said centralportion.

2. A set-screw guard comprising a resilient bridge having a centralportion and converging arms formed to engage a cylindrical body, and aflexible strip aflixed to the interior of the said central portion andadapted to be engaged With a set-screw projecting from said body.

3. A set-screw guard comprising a resilient bridge having a centralportion and converging arms formed to engage a cylindrical body, and aflexible strip secured at one edge to said central portion and adaptedto be engaged TGITCS with the head oi a set-screw projecting from saidbody.

4. A set-screw guard comprising a resilient bridge having a centralportion and converging arms formed to engage a cylindrical body, and aflexible strip secured at one edge to said central portion and formed tobe bent into a socket embracing a sot-screw head.

5. A set-screw guard comprising a resilient bridge having a centralportion and converging arms formed to engage a cylimlrieal body, and aflexible strip secured at one edge to said central portion and formed tobear on three sides of a set-screw head, said strip bcingextended sothat it niay be bent into engagement With another side of said head.

6. A set-screw guard comprising a resilient bridge having a centralportion and converging arms formed to engage a cylindrical body, and aflexible strip one edge of which is attached at a point between its endsto said central portion, the said strip having lree arms extending fromthe point of attachment, said arms being adapted to be bent against asetscreW head.

7. A set-screw guard comprising a resilient bridge having a centralportion, and resilient converging arms formed to automatically grasp acylindrical body, said bridge constituting the outer side of a segmentalspace at one side of said body, and a set-screav-cngaging deviceattached to the central portion ol the bridge and projecting into saidspace, said device and the resilient arms cooperating in holding thecentral portion of the bridge in position to guard the set-screw.

In testimony whereof I have allixed my signature in presence of twoWitnesses.

CHARLES E. PIVICRUIC.

\Vitnesses:

C. F. BROWN, E. BATounLnnn.

